In recognition of the ecological and cost impact of fossil fuels and other conventional energy sources, significant effort has been expended in developing methods for more efficient use of such energy sources. An important area of energy use for which greater energy efficiency is needed is the heating and cooling of spaces in which human activity is desired. Many approaches have been developed to decrease the amount heat transfer through the shell of such spaces. One of the most active and important areas of activity is the transfer of energy through fenestration where the activity has included use of window films or inserts, increasing the number of glazings per opening, and window treatments such as drapes, blinds, etc. While these approaches have shown considerable improvement in building energy efficiency, significant problems prevent more widespread and effective utilization.
Several problems exist in the approaches to minimizing heat transfer through fenestration. In particular for existing windows, it is desirable to maintain the optical transparency opening, operation of the window treatments and windows and the aesthetics of the interior view of the window while providing thermal insulation. Furthermore, reuse of the insulating materials is highly desirable so that new materials do not need to be purchased each season. When adding supplemental window elements such as films, film support elements and window treatments, ease of installation (including measurement and fabrication), reusability and storage and aesthetics during and after use are very important while obtaining the thermal and radiation insulation desired. With window films intended for creating an additional “dead air” space adjacent to the window as well as window treatments, accurate measurement of the film dimensions is necessary, often requiring the assistance of a professional with the associated added cost and time. Other window films, such as tints or low-e films, adhere directly to the window pane and encounter the similar issues.